1. Technical Field
The present invention relates to a technique for transporting a recording medium, on which image formation is performed, in a transport direction. In particular, the invention relates to a technique for adjusting a position of the recording medium in a width direction, which intersects the transport direction.
2. Related Art
In JP-A-10-086472, an image formation device is described in which images are formed on a continuous sheet of paper by a printing section which faces the continuous sheet of paper while the continuous sheet of paper is transported in the transport direction. In such an image formation device, if the continuous sheet of paper is slanted with respect to the printing section when being transported, the device may fail to perform appropriate image formation on the continuous sheet of paper. In the image formation device of JP-A-10-086472, the position of the recording medium is adjusted in the width direction by a skew correction section, whereby the slant of the transported continuous paper with respect to the printing section is corrected.
In order to appropriately adjust the position of a recording medium such as a sheet of continuous paper in the width direction, the position of the recording medium may be subjected to feedback control in accordance with a detection result of the position of an edge of the recording medium. In such a manner, the position of the transported recording medium can be appropriately adjusted for an image formation section forming images. In this case, in order to preferably form images on the recording medium, small positional changes of the edge of the recording medium need to be rapidly reacted to in order to stabilize the position of the recording medium. However, while the rapid reaction of a control system performing feedback control enables favorable image formation, the following problem is caused.
Since a positional change of the edge of the recording medium during image formation is relatively small, an amount of positional change of the recording medium made by the control system is also relatively small. However, in the image formation device, operations other than image formation may be performed. In such operations, sharp signals which are not used in image formation may be input to the control system. If the control system reacts rapidly to such signals, the position of the recording medium will be abruptly changed by the control system, which may cause the recording medium to become wrinkled.